Sexually fulfilled individuals tend to experience better sleep. After the orgasm, the body releases hormones, such as oxytocin and prolactin, which induce relaxed states leading to easier and deeper sleep.
Sex also reduces cortisol, a chemical associated with stress and PTSD-related symptoms and dreams. Studies show a noticeable increase of this effect, however, in men over women when dealing with heterosexual coitus.
All this being said, researchers were quick to point out the following: “[W]hen both people achieve orgasm during sex, the difference in sleepiness is no longer statistically significant…the association of sleepiness and sex for men in heterosexual relationships may, in part, reflect a disparity in satisfaction and orgasm achieved during sex with a partner.”
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